Device for removing vapors from annealing receptacles or furnaces



Jan. 17, 1928.

- T. STASSINET DEVICE FOR REMOVING VAPORS FROM ANNEALING RECEPTACLES 0R FURNACES Filed March 2 1927 Patent d Jan. 11, 1928.

UNITED STATES PATENT OFFICE.

THEODOR STASSINET, OF DIN SLAKEN, GERMANY, ASSIGNOR 1'0 SIEMENS-SCHUCKERT- WERKE GESELLSCHAFT MIT BESCHRKNKTEB .HAI'TUNG, BEBLIN-SIEMENS- STADT, A CORPORATION OF GERMANY.

DEVICE FOR REMOVING VAPORS FROM ANNEADING RECEPTAGLES 0R FURNACES.

Application filed March 2, 1927, Serial No. 172,128, and in Germany'December 12. 1925.

My invention relates to a device for removing vapors or mixtures of vapors from annealing receptacles or furnaces.

The bright annealing of metal articles is 5 frequently effected in annealing receptacles,

boxes, pots or furnaces through which during the heat treatment inert gases are passed which have no oxidizing action. Instead of inert gases neutral vapors may be em- 'ployed. The inert gas chosen may have a reducing action upon the material. to be an- .nealed and owing to the reducing'action of the inert gas upon the material to be annealed vapors may be formed. Steam may,

for instance, be produced by the action of hydrogen on oxide of iron, or liquids, such as oil or 'parafline adhering to the material to be annealed may be vaporized in the/interior of the furnace. Steam, oil vapors,

S0 parafline vapors and the like and mixtures of vapors in the annealing chamber have a very detrimental action upon the. material.

treated and the receptacle or furnace itself and it is therefore necessary to remove them- .25 from the annealing chamber. Suchvapors have hitherto been removed from the interior by constantly renewing the gases in the annealing receptacle or furnace.

- gases issuing from the receptacle or furnace then carry a portion of the vapors or mixtures-of vapors along. These escaping inert gases cool down considerably in the gas escape pipe on account of the low speed of the gas. The gas escape temperature remains mostly below the boiling temperature of the most easily boiling vapors. Only little of the most easily boiling vapor of the mixture of vapors is carried along by the escaping gas viz, so much only as the gas at its escape m temperature can contain in the saturated state. The vapors boiling with greater difliculty on the other hand remain almost comletely in the interior of the receptacle or mace until the more easily boiling vapors. are removed. In such apparatus a large quantity of inert gas is required in order to reduce the vapor contents of the inert gas of the annealing receptacle to a harmless proportion.

.By the device or apparatus according to, my invention only a very small quantity of .inert gas is required for the purpose. The inert gases with their vapors are according to my invention passed through the anneal- I The inert be made without: departing from the spirit ing receptacle or furnace and the gas 'discharge opening in such a manner that the temperature of the gases in the gas discharge branch is maintained above the highest boiling temperature of the vapors generated in the annealing receptacle or furnace.

The drawing affixed hereto illustrates an embodiment of my invention.

In the drawing is:

Fig. 1 an annealing receptacle, for instance, an electrically heated annealing furnace, in vertical sect-ion,

Fig. 2, the gas discharge branch on a larger scale, and

F'g. 3, a modified construction of a discharge branch. Like parts are indicated by like letters of reference in all the figures of the drawing. Referring to Fig. 1 of the drawing, a is the annealing receptacle or box of the 'furnace provided with the removable cover 6. c is the inlet branch for the inert gas and d the discharge branch for the gas.

This discharge branch (1 is accordingto my invention. provided with a special heat isolating layer or concentric bushing e, so that the gas escaping from the furnace is not subjected to cooling at the outer wall of the annealing receptacle. This is shown on a larger scale in Fig. 2 of the drawing.

Referring to Fig. 3 it will be seen that in order to make still. more sure that the gas does not become cooled when escaping from the receptacle an electric heating spiral f may-be located within the discharge branch.

Various modifications and changes may and the scope of the invention, and I desire, therefore, that only suchlimitations shall be placed thereon as are imposed by the prior art. I claim as my invention: '1. In apparatus .for removing. vapors from annealing receptacles through which inert gases are passed for the purpose of bright. annealing, means for keeplng the temperature-at the gas discharge branch of said receptacle above the highest boiling temperature of the vapors formed in said annealing receptacles 2. In apparatus for-removing vapors from annealing receptacles through which inert gases are passed for the purpose of bright annealing-a heat isolating covering around the gas discharge branch of said receptacle adapted to keep the temperature within it'above the highest boiling temperature of the vapors formed in said annealing receptacle.

3. In apparatus for removing vapors from annealing receptacles through which inert gases are passed for the urpose of bright annealing, a special device for the discharge branch of said receptacle adapted to keep the temperature in said branch above the highest boiling temperature of the vapors formed in said annealing receptacle. 4

4. In apparatus for removing va ors from annealing receptacles through w ich inert gases are passed for the purpose of bright annealing, an electric heating spiral provided at the gas discharge branch of said receptacle adapted to keep the temperature 

